SS-31 is a synthetic tetrapeptide — a chain of four amino acids with the sequence D-Arg-Dmt-Lys-Phe-NH₂. “Dmt” stands for 2′,6′-dimethyltyrosine, a modified version of the natural amino acid tyrosine. The molecular formula is C₃₂H₄₉N₉O₅, and it has a molecular weight of approximately 639.8 g/mol. Its CAS registry number is 736992-21-5. The peptide carries a net positive charge at physiological pH due to the arginine and lysine residues.

SS-31 belongs to a class of mitochondria-targeted tetrapeptides designed with mitochondrial membrane-compatible structural features. The peptide’s small size and alternating aromatic-cationic motif (positive charge, aromatic ring, positive charge, aromatic ring) give it membrane-permeable characteristics. It has a structural affinity for cardiolipin, a phospholipid found almost exclusively in the inner mitochondrial membrane. SS-31 is supplied as a white to off-white lyophilized powder that is soluble in water.

This product is strictly for research purposes only. Not approved for human or animal use.

PubChem Reference: View compound profile on NIH PubChem